(a) Field of the Invention
The present invention relates to a security association negotiation method of extensible authentication protocol (EAP) for authenticating a subscriber station user in a wireless portable Internet system. More particularly, the present invention relates to a security association negotiation method for generating an authentication key without an additional message exchange in an authentication scheme using EAP in a wireless portable Internet system.
(b) Description of the Related Art
As the next-generation communication technology, wireless portable Internet further provides mobility to a local data communication system such as a conventional wireless local area network (LAN) using a stationary access point (AP). There are various standard protocols that have been developed for supporting the wireless portable Internet, and the IEEE 802.16 working group attempts to establish an international standard of the wireless portable Internet protocol.
The authentication and authorization standard defined by the IEEE 802.16 establishes authentication functions for stations in a wide area network configured with wireless networks. In particular, since the subscriber station (SS) authentication function standardized by a privacy layer of the IEEE 802.16 is defined only for SSs within a fixed network, it is inappropriate for the authentication function to apply SSs or subscribers to be capable of supporting mobility, which is a current trend of mobile services. That is, in the wireless portable Internet system, the subscriber station has mobility, so it moves from a base station to another base station, and when a handover occurs, authentication key generation and security association negotiation need to be performed with a new base station.
As methods for authenticating a mobile terminal or a user, a PKM—(public key management) RSA method which utilizes a certificate of the mobile terminal and a PKM-EAP method for authenticating a mobile subscriber are defined. As such authentication methods, the PKMv1 protocol may be exemplified. According to the PKMv1 protocol, a terminal is authenticated by using a certificate of a mobile terminal in the IEEE 802.16 standard, and an authentication key (AK) and a traffic encryption key (TEK) are generated.
In addition, a newly defined PKMv2 protocol provides more various authentication methods than does the PKMv1 protocol. When classifying with reference to an authentication subject, the PKM-RSA method for authenticating a mobile terminal, the PKM-EAP method for authenticating a mobile subscriber, and PKM-RSA with EAP for authenticating both a mobile terminal and a mobile subscriber may be exemplified. According to the basic design concept of the PKMv2 protocol, the authentication key is generated by using a master key (MK) which may be obtained after authentication of a mobile terminal or a user.
However, according to the prior art, in the subscriber authentication methods such as EAP, the authentication key is generated after authenticating a mobile subscriber and exchanging the master key (MK) and random numbers of the base station and the subscriber station. In other words, it does not follow the basic design concept of the PKMv2 protocol. Therefore, when a handover of the subscriber station occurs, an additional message exchange is necessary, and the exchange of the random numbers through an authentication message is necessary for generating the authentication key for a new base station.
These problems of the prior art cause mobility of the subscriber station in the wireless portable Internet system to be reduced, and delay the data transmission.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.